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I wrote a Guide on how to install Arch Linux with BTRFS and (almost) Full Disk encrytion
(veprogames.github.io)
The beloved lightweight distro
In the Gentoo wiki it is also mentioned that "While it is true that Btrfs is still considered experimental and is growing in stability, the time when Btrfs will become the default filesystem for Linux systems is getting closer.". I don't know how many distros out there use Btrfs by default (never distrohopped), but it seems to become much more widely adopted than zfs.
https://wiki.gentoo.org/wiki/Btrfs#Features